Incinerator burner control



April 3, 1962 E- J. HAEDIKE INCINERATOR BURNER CONTROL Filed Aug. 26, 1959 2 Sheets-Sheet 1 /o l/ "T f 1775']? fur f /u/ardf/Vaedde aim 4 April 3, 1962 E. J. HAEDIKE INCINERATOR BURNER CONTROL 2 Sheets-Sheet 2 Filed Aug. 26, 1959 [171/5 HfUP fdward Jfla edze nited States 3,@27,853 Patented Apr. 3, 1962 3,027,853 INCINERATOR BURNER CONTROL Edward J. Haedike, Arlington Heights, 11L, assignor to Mid-Continent Metal Products Co., Chicago, 111., a corporation of Illinois Filed Aug. 26, 1959, Ser. No. 836,251 Claims. (Cl. 110-8) The present invention relates to an improved incinerator and to an improved apparatus and method for operating an incinerator and particularly to an improved burner assembly which automatically protects against the adverse effects caused by self ignition and combustion of materials within the incinerator.

The invention contemplates use with an incinerator of the type having a chamber where materials to be destroyed by combustion are placed and a burner usually of a gas fueled type directs a flame into the chamber and combustion occurs supported by air from a blower. The gaseous products of combustion pass out from the incinerator chamber through a flue connection and up a chimney. The incinerator is usually supplied with waste material over an extended period of time, may be overfilled, and frequently self ignition occurs. incinerators are often loaded by inexperienced operators such as is necessarily the case for installations in apartment houses, stores and similar non-industrial applications. The incinerator may be completely stuffed so as to block off the outlet to the flue and self ignition will result in smoke and fly ash being forced out through air intake openings into the room and into the burner which faces into the incinerator chamber. This material will tend to clog the burner and prevent its further effective use without cleaning and extinguish the pilot light. The heat generated within the incinerator chamber will heat up the burner and fan housings to a temperature beyond the safe level and cause damage.

A feature of the present invention is the provision of an incinerator having a burner in a housing with a blower mounted on the housing and a temperature responsive switch mounted on the housing connected to operate the blower alone when the housing temperature raises beyond a predetermined maximum, indicating self ignition and combustion within the incinerator. The temperature responsive switch is connected so that the blower can be operated alone and force the products of combustion out through the flue with the flow of blower air and cool the burner housing.

Accordingly, an object of the invention is to provide an improved incinerator arrangement and method of operation thereof which prevents the adverse effects encountered by self ignition and combustion within the incinerator chamber especially when the incinerator is overfilled.

Another object of the invention is to provide an improved burner and blower assembly for an incinerator or the like wherein the mechanism is protected against overheating and protected from being fouled by the flow of fly ash and products of combustion into the burner.

Another object of the invention is to provide an improved burner and fan assembly for an incinerator with electrical operating circuits which permit normal operation of the burner and fan and which obtain automatic operation of the fan alone without operation of the burner upon self ignition of the incinerator to protect the parts against excessive temperatures and foreign materials from the incinerator.

Other objects and advantages will become more apparent with the teaching of the principles of the invention in connection with the disclosure of the preferred embodiment thereof in the specification, claims and drawings, in which:

FIGURE 1 is a vertical sectional view taken through an incinerator of the type embodying the principles of the present invention;

FIGURE 2 isa vertical sectional view taken substantially along line 11-11 of FIGURE 1;

FIGURE 3 is a side elevational view of a burner and blower assembly showing the operating circuit in diagrammatic form;

FIGURE 4 is a diagrammatic showing of the operating electrical circuit for the mechanism of FIGURE 3, with the circuit to the blower being completed as caused by overheating of the burner housing; and

FIGURE 5 is a diagrammatic illustration of the electrical circuit, similar to FIGURE 4, but showing the position of the switches when the burner housing is cool and when the burner and blower are operating for normal incinerator operation.

As shown on the drawings:

As shown in FIGURES l, 2, an incinerator 9 is built of suitable material such as fire bricks 10 enclosed in a sheet metal housing 11. Within the incinerator is a primary combustion chamber 12 and mounted in an opening 13 in the incinerator wall, is a burner 14 with a burner nozzle 14a projected toward the primary chamber 12.

At an end of the incinerator is a charging door 15 and materials to be destroyed are inserted through the charging door and rest on a grate 16 with ash dropping down to an ash chamber 17 where it can be removed through an ash clean out door 18, which is provided with a suitable air intake draft opening.

The incinerator is illustrated with an opening 19 leading from the primary combustion chamber 12 to a secondary chamber 22. A wall 21 extends down from the top of the incinerator into the chamber 22 and has a draft vent 20 therein. The products of combustion flow up in the primary chamber through the opening 19 through the secondary chamber 22 and out through a flue pipe 23 which suitably connects to a chimney. As will be observed, stufiing the primary chamber 12 will partially close the opening 19 to the secondary chamber and with self ignition the smoke and fly ash and products of combustion will escape into the room and will foul the burner 14 and possibly put out the pilot light within the burner. Furthermore, the burner housing will become overheated and the burner damaged. A feature of the present invention is the automatic provision of a forced draft of air through the primary chamber 12 when the temperature of the burner housing increases beyond the predetermined maximum.

The burner is illustrated with its operating circuitry in FIGURES 3 through 5. The burner 14 is provided with a housing 24 having a flange 25 for mounting it on the incinerator wall. Mounted on the burner housing and being substantially integral therewith is a fan or blower 26 having a blower motor 26a and a blower scroll 26!). During normal operation both the blower and burner operate with the blower driving air through the housing 24 of the burner. During automatic safety operation, in the event of overheating of the housing 24, the blower operates alone to force air through the housing 24 to cool it.

The burner 14 may take various forms of means for generating heat energy within the incinerator chamber and is preferably in the form of a gas burner supplied with fuel through a pipe 27 controlled by a main shut off valve 28. Operating electricity is supplied through a line 29 connected to the burner and blower by a suitable terminal connector box.

The blower motor 26 has a connector box 31 to which is connected a lead 33 leading from a temperature responsive switch A. Another lead 30 connects to the other terminal of the box 31 from the other side of the supply line 29. For safety operation of the blower, a first circuit 31. connects through the thermal responsive switch A to the blower motor 26. The switch A is mounted on the burner housing 24 as shown schematically in the drawings, and operates responsive to the temperature of the burner housing. When no air is flowing through the burner housing the temperature of course rises as the temperature within the incinerator chamber 12 rises.

Normal incinerating operation of the burner assembly is achieved through switches B and C. When the switch B is closed, a second circuit 34 operates the blower motor 26 and as it reaches operating speed, switch C, which is a centrifugal switch, closes to close a third circuit 36 to open a gas valve 37 causing the burner to operate. The burner may be ignited electrically or by a pilot light.

The manually operated'control switch B is preferably a manually closed timer switch so that the timer switch can be preset for a desired period of closure and the incinerator left unattended.

The temperature responsive switch A has a cold position and a hot position with a switch arm 40 making circuit with a terminal 38 in the cold position and making circuit with a terminal 39 in the hot position. FIGURE 3 illustrates the condition of the switches when the burner is not operating and when there is no heat in the incinerator chamber.

FIGURE 4 illustrates the condition of the switches when the material in the incinerator chamber self ignites and the burner housing heats to a temperature to actuate the switch A to its hot position. As illustrated in FIGURE 4, the first circuit 32, which leads to the blower from the supply line 29 through the hot terminal 39 of the switch A and through the line 33, is completed to start the blower motor 26. The blower operates alone and the circuit to the gas valve will remain open. Centrifugal switch C closes as the blower reaches operating speed, but since switch B is open the burner does not operate. The blower continues operation until the burner housing is cooled and the switch A returns to its cold position, as illustrated in FIGURES 3 and 5. Switch A is preferably a snap action switch.

FIGURE 5 illustrates the condition of the switches during normal incinerator operation. Since the blower is operated during operation of the burner, the burner housing will not become heated and switch A will remain in its cold position. The timer switch B is closed and the circuit 34 through the cold terminal 38 of the switch A is closed to the blower 26. As soon as the blower reaches operating speed, the centrifugal switch C will be closed thereby completing the circuit 36 to the gas valve 37, igniting the burner.

Thus the two position switch A permits completing the circuit to the blower when the switch is in the hot position, without operating the burner. When the switch A is in its cold position, it forms a part of the circuit to the blower through the time switch B. With the circuit as shown, switches A and B provide means for breaking the circuit to the burner during operation of the blower alone. As will be appreciated by those skilled in the art in some circumstances it may be desirable to employ other switch arrangements for breaking the circuit to the burner during operation of the blower alone such as by energizing the blower through a separate circuit during normal operation of the incinerator and not through the switch A, with the separate circuit being energized by a separate timer switch, such as by making switch B a two circuit switch.

Thus it will be seen that we have provided an improved incinerator and burner assembly therefor which meets the objectives and advantages hereinbefore set forth. The mechanism is well adapted to reliable and simple operation and operates automatically so that the incinerator can be used by non-skilled personnel. Disadvantages heretofore encountered by self ignition of incinerators which caused damage to the burner and blower, created operating hazards, and caused the escape of smoke and soot into the incinerator room are obviated.

It will be understood that the fan is operated normally by a first means during regular burner operation, and can also be operated by a second means responsive to the increase in temperature above a predetermined maximum temperature. The temperature rise in the incinerator may be measured in various ways, and in the preferred arrangement shown is measured by detecting the temperature rise of the burner housing above a predetermined maximum, inasmuch as that reflects the temperature within the incinerator, and offers the advantage of insuring that the parts on the housing do not overheat.

The drawings and specification present a detailed disclosure of the preferred embodiments of the invention, and it is to be understood that the invention is not limited to the specific forms disclosed, but covers all modifications, changes and alternative constructions and methods falling within the scope of the principles taught by the invention.

I claim as my invention:

1. A burner assembly for an incinerator or the like comprising a burner for generating heat energy Within an incinerator chamber to cause combustion of material therein, a housing for said burner, a blower mounted on the housing for directing air through the burner into the chamber, an electrically operated fuel control for the burner, a main control switch, a temperature responsive switch mounted on the housing and having a cold position and a hot position, a first circuit connected to the blower through the hot position of the switch so that the blower will be operated to protect the burner at a predetermined temperature of the burner housing, a second circuit connected to the blower and the main control switch through the cold position of the temperature responsive switch for normal operation of the blower, a switch responsive to blower operation and being closed in response to blower operation, and a third circuit including said main switch, said fuel control, and said blower responsive switch, said first circuit closed by the temperature responsive switch when the housing reaches a predetermined temperature so that the burner and blower will be protected, and said second and third circuits closed by closing said main switch for normal operation of the incinerator.

2. A burner assembly for an incinerator or the like comprising a burner for generating heat energy within the incinerator chamber to cause combustion of material therein, a housing for said burner, a blower mounted on said housing for directing air through the burner into the chamber, an electrically operated fuel control for the burner, a main control switch, a. temperature responsive switch mounted on the housing and closing at a predetermined maximum housing temperature, a first circuit connected to the blower through the temperature responsive switch, a second circuit connected to the blower and to said main control switch, a third circuit connected to the main control switch and to said electrically operated fuel control, said first circuit closed by the temperature responsive switch when the housing temperature reaches a predetermined temperature so that the burner and blower will be protected, said second and third circuits closed by closing said main switch for normal operation of the incinerator, and means for opening the third circuit to the burner fuel control when said first circuit is closed.

3. A burner assembly in accordance with claim 2 in which said main control switch is a timer switch presettable for the different periods of operation of the blower and burner.

4. The method of operating an incinerator having a burner and a blower which comprises the steps of operating both the blower and burner during normal operation, measuring the temperature of the burner, and operating the blower alone when the burner temperature rises above a predetermined maximum due to com 5 tion of the products in the incinerator to protect the burner and blower.

5. An incinerator assembly comprising an incinerator chamber with an opening for the exhaust products of combustion, a combustion supporting air fan connected to the chamber to circulate air through the chamber and out of said exhaust opening, a burner having a fuel supply means connected to direct combustible fuel into said chamber, first means for operating said fan during normal operation of the burner with fuel supply to the chamber, and second means for operating said fan responsive to a predetermined maximum temperature in said chamber to start a flow of air through said chamber at said maximum predetermined temperature such as is caused by combustion of products Within the chamber.

References Cited in the file of this patent UNITED STATES PATENTS 1,926,714 Culbertson Apr. 18, 1930 1,968,581 Williams July 31, 1934 2,086,608 Detlar July 13, 1937 2,168,581 Bergey Aug. 8, 1939 2,335,471 Ashcraft Nov. 30, 1943 2,640,648 Judson June 2, 1953 2,882,534 Jauch et al. Apr. 21, 1959 

